The present invention relates to a detector system for identifying among multiple magnetizable markers that may be embedded in other materials for sorting, authenticating, and/or sensing operations.
In the manufacture of a multi-component product, for example, packaged pharmaceuticals intended for over-the-counter sale, it is important to verify that the package includes a paper insert listing the characteristics of the drug and instructions for safe use. While considerable care is taken in placing the insert into the package, ideally, its presence in the package could be verified after the package is sealed. One way of doing this is by weighing the package to detect the additional weight of the insert. For light inserts or products that vary in weight, such an approach is unreliable.
The grandparent to the present application describes a method of verifying the presence of a component of a manufactured product by incorporating a small amount of filamentized magnetic material into that component, the latter whose presence may be detectable at a distance. The filaments are of low cost and may be freely dispersed into the material of the component for manufacturing convenience and may be remotely sensed even through packaging or the like. Unlike “magnetic stripe” type techniques for recording data, this invention allows identifying the component without direct contact.
While the ability to sense an individual component in a manufactured product is valuable, often it may be necessary to sense combinations of components or to distinguish between different component types. The parent to the present application describes a method of communicating not simply presence or absence of a component in an assembly, such an operation that requires only the conveyance of a single binary “bit” of information, but of distinguishing between different components containing different types of magnetizable filaments, each conveying one bit of multiple bits of information.
The number of different types of magnetic filaments that can be distinguished using previous techniques is limited. What is desired is an improved detection technique that allows a large number of different components to be distinguished from one another using magnetic marking techniques.